Adolf Hitler
Adolf Hitler (1889 - 1945) in Munich in the spring of 1932Getty Images

One of the co-authors of the book, Hitler's Last Day: Minute by Minute, has said that reports which suggested that the fuhrer had a "micropenis" were farfetched. Historian Emma Craigie told The Independentthat there was no evidence to suggest that the German dictator had a "micropenis" linked to his medical condition called hypospadias, a birth defect that is believed to occur in 1 in 300 men.

"[Adolf] Hitler himself is believed to have had two forms of genital abnormality: an undescended testicle and a rare condition called penile hypospadias in which the urethra opens on the underside of the penis," the authors, Emma Craigie and Jonathan Mayo, said in their book.

The authors found Hitler's medical reports from 1923 when he was jailed for a brief period after a failed coup. The prison's medical officer, Josef Steiner Brin, reportedly noted that Hitler "suffered from right-side cryptorchidism [absence of one or both testes from the scrotum]" but was otherwise "healthy and strong". Hitler's personal doctor, Theodor Morell, reportedly diagnosed Hitler with hypospasdias, while giving him hormones, amphetamines and cocaine to boost his sex drive.

German historian, Volker Ulrich, has also claimed he uncovered prison records that showed Hitler had an undescended testicle on the right side. Professor Peter Fleischmann of Erlangen-Nuremberg University too has made the claim.